Fatty acids are commercial commodities available from a number of natural sources. Similar synthetic acids can be synthesized from olefins by hydrocarboxylation of the olefins over catalysts, and also by hydroesterification of olefins over catalysts, followed by hydrolysis. It happens that such procedures often result in acids of varying linearity, i.e. the product may contain a quantity of linear, that is normal, acids along with acids of branched structure. The degree of normality obtained can be influenced to some extent by reaction conditions, as well as by the olefin feed stock, i.e. the amount of branching and the presence of terminal rather than internal unsaturation. However, there are generally limits to normality obtainable by reaction modifications, and there is the matter of availability and cost of olefin feed stock, or the expense of distillation or other procedures to obtain a more suitable feed stock. Moreover, a range of acids is often produced, e.g. over a carbon atom range of 11 to 13 carbon atoms. Because of the range of boiling points resulting from molecular weight differences, it is often impractical to use distillation as a means of separating the acids in accordance with linearity.